I only have one quibble with what is sure to be a stimulating and, let's face it, fun event. Is the cult of celebrity, the commodification of art and the business of success really Warhol's legacy?

It's a side of Warhol that has recently been highlighted by curators who are, I'm guessing, having a laugh by reacting against those who emphasise his serious side. It was also evident at the Hayward's recent Warhol show. I, by contrast, am struck by the darkness and desolation of the artist's vision – above all his Death and Disaster paintings of the 1960s: stark images of car crashes and suicides, grainily silkscreened from news photos and bathed in cool abstract fields of empty yet emotional colour.

I can see why people might want to rebel against the idea of Warhol as a serious artist. But the other night I came across a film that concentrated on the superstar Nico during a Velvet Underground jamming session in Warhol's Factory. She's disengaged, chatting and occasionally banging on a tambourine. When the camera slowly pulls back you see the rest of the band – and a small child, who I think is Nico's young son. It is disturbing to see this unhappy child sitting with a rock band that's rehearsing dark and disturbing anthems in such an adult setting. It makes you uneasy about the Factory, about Warhol. Then you wonder: who made this film? The bold and simple nature of it, the concentration on one person, the lack of sideways camera movement or editing, makes it pretty clear it is a film by Warhol himself. He is delivering this report to history, recording for posterity a telling and worrying fact about his world.

How complex a person, how subtle an artist, how serious a visual historian does that make Warhol?